| 摘要 |
<p>A method of patterning a perforated screen printing screen (9) having a lacquer coating filling its perforations (10) using a laser engraving device includes the steps of locating the position of the locus of aligned perforations (10), aligning an engraving head (7) of the laser engraving device with the locus of the perforations (10) and then selectively actuating the laser to remove the lacquer individually from those perforations (10) which it is required to unblock. The laser engraving device includes a scanner (1,2) for scanning the laser engraving head (7) over the surface of the screen (9), a detector (8) for detecting the locus of the perforations (10) extending in the scanning direction of the laser engraving head (7) and the location of each perforation (10) in the scanning direction, alignment devices (4, 5, 6) responsive to the output of the detector (8) to align the laser engraving head (7) with the locus of the perforations (10) detected by the detector (8), and a laser actuation control (20, 21, 24) to enable the laser to be actuated only when it is aligned with the individual perforations (10).</p> |
